Investigate the properties and symmetries of quadrilaterals.
Select a type of quadrilateral, and use the buttons below to optionally show the diagonals, and add markings to indicate the important angle, side and diagonal properties. The Fold and Rotate buttons invoke animations to aid investigation of the symmetry of the shape.
The shape can be changed by dragging the blue vertices, and rotated by dragging the green vertex (when present).
Choose a starting quadrilateral shape. Can you change it into another standard quadrilateral? Use the grid and the decorations to guide you.
Check that the listed properties remain true as you drag the vertices, and use the Update Shape button to lock in the properties of the new shape if desired.